Weird dyno tuner

[Omega]

I finally got around to getting some actual numbers for my Talon. I tuned last fall with the LM-1 and was very happy with the results, in fact they were too good.. the car had little to no traction. I went to a guy that I really though knew his shit... certified in all sorts of stand alone systems and such.

The first run was 264 HP with a AFR that started very lean, but then very quickly went rich as the boost came on. It was hovering around 12:1 with a few lean/rich sections from there. The guy was not happy with that and said that he wanted to see a nice 13.5:1 ratio accross the board and that he likes a rich condition before the boost hits. He also said that running the way I had it, I would blow the engine?

After I got the numbers close to what he wanted in terms of AFR, I was left with 253HP and 23x TQ.

Am I crazy in thinking that he hasn't got a clue? Why would he want me to run more lean than what I was and make LESS power!

 

[98spydert]

12.5:1 is actually better for our engines. I'd take it back and have it richened up because 13.5:1 is too hot. Do you have a pyrometer? I bet your temps are around 1700 near peak power.

Another thing, the lower power output could be the result of the timing being pulled do to knock(do to running too hot)

 

[rabidfox]

maybe you can run 13.5:1 on race gas, but I wouldn;t go near that on pump....jesus. 12:1 is a bit lean for pump gas, most people ont his board tune for 12.5:1 or a bit higher. I think you're knocking.

 

[Omega]

EGT's are around 1400. On the highway at high speeds it goes up to ~1500. The EGT didn't change much if any before and after the "tune" just less power.

Before the dyno I was getting about 32 deg of timing (i think) It was pretty high.

I think I need to whip out the LM1 again and retune this thing.

 

[rabidfox]

are you sure the 32 deg of timing wasn't from you letting off the gas at high RPM's? can you post a log of the run. It's been discussed in quite a few threads before that EGT's can't really tell you too much, for example, where did you mount the probe? If it's mounted in the downpipe it'll see temps 150-200 deg lower thatn runner number 1. Go to another dyno that has a wideband O2 and a guy that has a clue. If you can't post the logs, then post the timing advance at 500 rpm intervals or so, that should help out.

oh yeah, reverse my numbers in my previous post. 12.5:1 is a tad lean and shouldn't be run on the street unless you're monitoring it all the time, 12:1 is safer.

 

[Omega]

As I said, the 32 was from memory.. I'll log a run or two tonight with the loger and see what the car is doing now. If I can find the old logs then I will post those as well.

The probe is in the far right runner (#1?). It is the autometer standard probe, which I hear is "slow". Perhaps someone has the "fast" probe part number handy.

This guy's mindframe was almost as if 12:1 was lean and 13:1 is rich... strange stuff.

I knew what you meant.

 

[rabidfox]

yeah, this gut sounds like an asshat, it's air:fuel ...the more air the leaner, you might want to retune it yourself or go to a dyno that doesn't employ tards, it sounds like you know more than this guy about tuning. Just start leaning it ut across the board until you get knock(or timing pulled), then richen it up justa tad to be safe and you should be fine. Maybe go to a dyno to get a race gas map, but for the street, run what's safe.

 

[98spydert]

asshat

Yeah let's see some logs, then you can go kick that guy sqaure in the ballz... after he fixes it